Swords & Wizardry: Complete is very similar to 1e, without using most of the stuff commonly ignored in 1e like weapon vs. ac, weapon speeds, etc...
It has rules for both descending ac & ascending with base-to-hit bonuses.
Basic Fantasy is good too. Core rules is more like B/X with separation of race & class (also ascending AC and BtH). On their websites are plenty of rules for the advanced races and classes. All free .pdf, very cheap print products.